ECCENTRICITY COMPENSATION APPARATUS BASED ON FREQUENCY RESPONSE CHARACTERISTICS OF ACTUATOR OF DISK DRIVE SERVO SYSTEM

摘要

AN ECCENTRICITY COMPENSATING APPARATUS OF A DISK DRIVE SERVO SYSTEM USING THE FREQUENCY RESPONSE CHARACERISTICS OF AN ACTUATOR FOR ACTUATING A HEAD TO A POSITION ON A DISK TO READ DATA ON OR REPRODUCE DATA FROM THE DISK, THE APPARATUS INCLUDING : AN ERROR DETECTOR THAT DETECS A POSITION ERROR BETWEEN A REFERENCE HEAD POSITION AND AN ACTUAL POSITION OF THE HEAD ON THE DISK; A FIRST COMPENSATION CONTROLLER THAT RECEIVES THE POSITION ERROR FROM DETECTOR AND CHANGES THE ACTUAL POSITION OF THE HEAD I ORDER TO COMPENSATE FOR THE POSITION ERROR; A SECOND COMPENSATION CONTROLER THAT GENERATES AND OUTPUTS A CONTROL VALUE TO COMPENSATE FOR ECCENTRICITY WHICH VARIES DEPENDING ON THE PHASE OF A SPINDLE THAT ROTATES THE DISK; AND A GAIN/PHASE ADJUSTER THAT ADJUSTS THE GAIN AND PHASE OF THE CONTROL VALUE OUTPUT FORM THE SECOND COMPENSATION CONTROLLER ACCORDING TO A DISK REPRODUCTION SPEED, WHEREIN A DRIVE SIGNAL OF THE ACTUATOR IS OBTAINED BY SUMMING TOGETHER SIGNALS OUTPUT FROM THE FIRST COMPENSATION CONTROLLER AND THE/GAIN PHASE ADJUSTER. THE ECCENTRICITY COMPENSATION APPARATUS CAN SIMPLY COMPENSATE FOR ECCENTRICITY AT VARYING REPRODUCTION SPEEDS BY ADJUSTING CONTROL DATA ESTIMATED FOR ECCENTRICITY COMPENSATION AT SPECIFIC REPRODUCTION SPEED BASED ON THE FREQUENCY REPONSE CHARACTERISTICS OF AN ACTUATOR.